Machine for unrolling and laterally aligning ribbons

ABSTRACT

A machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, particularly for conveyor-belt cutting units and the like, comprising a supporting element that supports a roll of ribbon, a motorized device for unrolling the roll constituted by the ribbon, the machine further comprising a first assembly for reading the tension of the unrolled ribbon in order to adjust the motorized device so as to eliminate the tension of the unrolled ribbon, means for the lateral sliding of the unrolled ribbon, which is substantially free from tensions, for its alignment on a worktable, and a second assembly for reading the lateral deviation of the unrolled ribbon.

The present invention relates to a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, particularly for conveyor-belt cutting units and the like.

BACKGROUND OF THE INVENTION

In the field of the preparation of products made of synthetic materials, numeric-control cutting is performed in individual or multiple layers on conveyor-belt machines.

The processed materials are usually supplied in rolls, which are wound in a manner that is not perfectly aligned. Therefore, in order to feed numeric-control cutting machines it is necessary to first align the ribbon of material unwound from the rolls.

Currently, the most commonly adopted known solutions for cutting tables or for spreading units (which prepare mats of material in layers to be then arranged on the cutting machine) substantially use a system which, by being based on the feedback of alignment sensors arranged on the edge of the ribbon, moves laterally the support on which such roll is arranged, in order to correct the deviation caused by the uneven rolling of the ribbon of material in the roll.

These known solutions are not devoid of drawbacks, which include the fact that it is necessary to resort to the movement of a structure that is strong enough to be able to bear even quite heavy rolls and can perform lateral movements on the order of several centimeters.

Another drawback of known solutions consists in that such structure is onerous to duplicate if one wishes to align and overlap a plurality of layers of material.

More specifically, spreading units are devices capable of preparing mats of any number of layers by superimposing the material that is unwound and trimmed from a roll with an alignment system such as the one described earlier, and an unrolling system that eliminates the tensioning of the ribbon of material unwound from the roll.

Progressive reduction of the size of the cutting batches imposed by the market makes it more convenient to perform cuts on a reduced number of layers.

The times and costs of spreading operations are in fact justified only above a certain quantity of layers, which cannot be performed continuously and efficiently.

By instead supplying the cutting unit with a limited number of layers, unwound respectively from an identical number of unwinding and alignment units, one would obtain the best compromise between the productivity of the cut and the necessary flexibility in consumption of material.

SUMMARY OF THE INVENTION

The aim of the present invention is to eliminate the drawbacks cited above, by providing a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, particularly for conveyor-belt cutting units and the like, that is simple and efficient.

Within this aim, an object of the present invention is to provide a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like that can be multiplied for several rolls of material to be fed in layers on the cutting unit.

Another object of the present invention is to provide a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like that is highly reliable, relatively simple to provide and at competitive costs.

This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, particularly for conveyor-belt cutting units and the like, comprising a supporting element that supports a roll of ribbon, a motorized device for unrolling the roll constituted by said ribbon, characterized in that it comprises a first assembly for reading the tension of said unrolled ribbon in order to adjust said motorized device so as to eliminate the tension of said unrolled ribbon, means for the lateral sliding of said unrolled ribbon, which is substantially free from tensions, for its alignment on a worktable, and a second assembly for reading the lateral deviation of said unrolled ribbon.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become better apparent from the description of a preferred but not exclusive embodiment of a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, according to the invention, illustrated by way of non-limiting example in the accompanying drawing, wherein:

FIG. 1 is a side elevation view of a machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the FIGURE, the machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, generally designated by the reference numeral 1, comprises a supporting element 2, which supports a roll 3 of ribbon 4, a motorized device 5 for the unrolling of the roll 3 constituted by the ribbon 4, and a first assembly 6 for reading the tension of the unrolled ribbon 4 in order to adjust the motorized device 5, so as to eliminate the tension of the unrolled ribbon 4.

The machine 1 further comprises means 7 for the lateral sliding of the unrolled ribbon 4, substantially free from tensions, for the alignment thereof on a worktable 8, and a second assembly 9 for reading the lateral deviation of the unrolled ribbon 4.

The motorized device 5 comprises an unrolling roller 10, which can rotate about its own axis parallel to the axis of the roll 3 and on which the unrolled ribbon 4 is partly wound.

The motorized device 5 further comprises first motor means 11, which are associated with the unrolling roller 10 by means of a belt drive 11 a.

The first reading assembly 6 comprises at least one redirection roller 12, whose axis is parallel to the axis of the roll 3 and on which the ribbon 4 unrolled in output from the unrolling roller 10 is partly wound.

The first reading assembly 6 comprises at least one lever 13 for supporting the redirection roller 12, which is pivoted at one end 13 a to the redirection roller 12 and at the other end is associated rotatably with a fixed portion of the machine 1.

The first reading assembly 6 comprises a sensor, not shown, for measuring the angular deviation of the supporting lever 13 under the action of the ribbon 4 with respect to a reference position for actuating the first motor means 11.

The means 7 for lateral sliding comprise advantageously a first idle roller 15 and a second idle roller 14, which have parallel axes and have a variable center distance, and through which the unrolled ribbon 4 in output from the redirection roller 12 is inserted.

The first idle roller 15 is associated rotatably with a fixed portion of the machine 1 and the second idle roller 14 is pressed toward the first idle roller 15 by a piston 15 a to close and open the second idle roller 14 on the first idle roller 15.

The first idle roller 15 and the second idle roller 14 are associated with a system of substantially straight guides 16 for their axial sliding.

The axial movement of the first idle roller 15 and of the second idle roller 14 on the system of guides 16 occurs by way of second motor means 17, for example by means of a screw-and-nut coupling 18.

The second reading assembly 9 comprises a set of photocells, not shown, for detecting the position of the edge of the ribbon 4 on the plane of the worktable 8.

The second reading assembly 9 can comprise, as an alternative to the photocell system, a vision system, not shown, for detecting repetitive markings on the unrolled ribbon 4 in output from the first idle roller 15 and from the second idle roller 14.

With reference to the figure, operation of the machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, according to the invention, is clear and evident from what has been described above.

In particular, it must be noted that the ribbon 4 unrolled from the roll 3 can be moved laterally by virtue of the action of the axial movement of the first idle roller 15 and of the second idle roller 14, since it has no tension due to its unrolling.

In practice it has been found that the machine for unrolling and aligning ribbons of fabrics, synthetic material and the like, according to the present invention, achieves fully the intended aim and objects, since it allows the unrolling and alignment of a ribbon from a roll in a manner that is simple and efficient, and can be multiplied for several rolls of material to be fed in layers on the cutting unit.

The machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. MI2007A002158 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs. 

1-8. (canceled)
 9. A machine for unrolling and aligning ribbons of fabrics, synthetic materials and the like, particularly for conveyor-belt cutting units and the like, comprising a supporting element that supports a roll of ribbon, a motorized device for unrolling the roll constituted by said ribbon, further comprising a first assembly for reading the tension of said unrolled ribbon in order to adjust said motorized device so as to eliminate the tension of said unrolled ribbon, means for lateral sliding of said unrolled ribbon, which is substantially free from tensions, for its alignment on a worktable, and a second assembly for reading the lateral deviation of said unrolled ribbon.
 10. The unrolling and aligning machine according to claim 9, wherein said motorized device comprises an unrolling roller whose axis is parallel to the axis of said roll and on which said unrolled ribbon is partly wound, first motor means which are associated with said unrolling roller by means of a belt drive, said unrolling roller being able to rotate about its own axis.
 11. The unrolling and aligning machine according to claim 10, wherein said first reading assembly comprises at least one redirection roller whose axis is parallel to the axis of said roll and on which said ribbon, unrolled in output from said unrolling roller, is partly wound, at least one lever for supporting said redirection roller, which is pivoted at an end to said redirection roller and at the other end is rotatably associated with a fixed portion of the machine, and a sensor for measuring the angular deviation of said supporting lever under the action of said ribbon with respect to a reference position for the actuation of said first motor means.
 12. The unrolling and aligning machine according to claim 9, wherein said means for lateral sliding comprise a first idle roller and a second idle roller, whose axes are parallel with a variable center distance and through which said unrolled ribbon in output from said redirection roller is inserted, said first idle roller being associated rotatably with a fixed portion of said machine and said second idle roller being pressed toward said first idle roller by a piston for closing and opening said second idle roller on said first idle roller.
 13. The unrolling and aligning machine according to claim 12, wherein said first and second idle rollers are associated with a system of substantially straight guides for their axial sliding.
 14. The unrolling and aligning machine according to claim 12, comprising second motor means for the movement of said first and second idle rollers on said system of guides by means of a screw-and-nut coupling.
 15. The unrolling and aligning machine according to claim 9, wherein said second reading assembly comprises a set of photocells for detecting the position of the edge of said ribbon on the plane of said worktable.
 16. The unrolling and aligning machine according to claim 12, wherein said second reading assembly comprises a vision system for detecting repetitive markings on said unrolled ribbon in output from said first and second idle rollers. 